Cross-Linking of Multi-Walled Carbon Nanotubes with Polyethylene Glycol

In this paper a new approach to cross-link two individual multi-walled carbon nanotubes (MWCNTs) by a nucleophilic substitution of brominated MWCNTs using polyethylene glycol anion was introduced. The functionalized MWCNTs were characterized using thermogravimetric analysis (TGA), energy-dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), and Fourier transform infrared (FT-IR) spectroscopy. It is found that polyethylene glycol act as cross-linking agents to interconnect or cross-link the MWCNTs within and among the bundles, as demonstrated by TEM analysis, and few defects will be induced to the nanotube sidewalls. After cross-linking of PEG, the functionalized MWCNTs are still insoluble in any solvent; however, the morphologies of the cross-linked MWCNTs were largely intact, undoubtedly which will provide a useful way to construct nanoscale devices with MWCNTs in the future.